The intense exercise regimen, crossfit is. Very popular among adults nationwide. Now, there's a version for kids growing across the country. But we ask the question, is it safe for them to work out like mom and dad? Abc's paula faris has more. Reporter: It's a military-style workout. And among the extreme exercise fanatics, all the rage. Look it out over top. Reporter: Now, crossfit, the program that thrives on pushing adults to the brink -- crossfit. Reporter: Is available for kids. Before their leg lizards all the way down. Reporter: And has wondering, is intense cross training fit for kids. Crossfit for adults is hard-core. Is crossfit for kids equally as hard-co hard-core? No. It's scaleable. We teach the movement. Reporter: Aaron runs evf crossfit, in new york city. 1 of 900 crossfit programs in the u.S. As long as there's proper coaching, we teach them the basing movement, there's no chance of them having a problem. Reporter: But pediatrics sports medicine specialist, paul stricker, says it can be too intense for some bones. If you have the wrong child at the wrong time with the wrong amount of experience and the wrong supervision, it can be quite risky. Reporter: In a statement, crossfit kids adds, our intention is to make children safer in their daily lives. Such as when lifting a backpack or on the field of play when they have to run, cut, jump, et cetera. And the parents we talked to were thrilled. What kind of difference have you noticed in your boys in the last month and a half? I think the focus. I think the energy and just -- they love it. Incredible. I can run faster. Reporter: You're running in faster in p.E. Now? Reporter: And coach eric's daughter is in a class for 8 to 12 years old. She enjoys it. She's doing it for herself. Every parent's dream. Reporter: Now, the instructors are really watching these kids to make sure they're not pushing themselves too much. But I saw a group of kids who were just excited about fitness and were very vocal in how much of a positive impact it is having on their life. There's a risk. But there's a risk in any sport that our children play. So, you know, they're really tailoring it. It seems to make sense. They're focusing on movement. Movement. And the kids are really excited. Thank you, paula.

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